surgerymax
Iron
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First we need an anabolic base so we can essentially nuke muscle loss and also this further drives up thermogenic activity
Green = Anabolic BaseBlue = Main fat loss drivers
Purple = Appetite suppression agents
Yellow = Mechanism explanation
Testosterone (300mg/week) + Trenbolone (70mg/week)
More on microdose tren and why it fucking mogs hereTestosterone’s metabolic effects are both direct (via AR on metabolic tissue) and indirect (via LBM accretion which raises absolute EE). Direct AR-mediated effects include increased skeletal muscle mitochondrial biogenesis, enhanced Na+/K+-ATPase activity, and promotion of fat oxidation over glucose oxidation
'Testosterone deficiency induced by gonadal steroid suppression in healthy young men resulted in a significant decline in rates of lipid oxidation, with parallel changes in resting energy expenditure and increased adiposity. Short-term transdermal testosterone treatment stimulated whole-body fat oxidation and reduced fat mass in testosterone-deficient men. (J Endocrinol, 2013)'
In young men exposed to severe caloric deficit, supraphysiological testosterone (200 mg/week) preserved lean mass and nitrogen balance and promoted erythropoietic and molecular anabolic adaptations
Additionally ghrelin elevation during the deficit was attenuated with testosterone further helping with appetite suppresion
Trenbolone’s thermogenic mechanism is distinct from testosterone’s. Its exceptionally high AR binding affinity (5× testosterone) drives strong transcriptional upregulation of UCP3 in skeletal muscle. UCP3 uncouples oxidative phosphorylation, allowing electron transport without proportional ATP synthesis , energy is dissipated as heat.
This is the mechanistic basis for the profuse diaphoresis that is the clinical hallmark of trenbolone use , you are literally radiating metabolic heat from skeletal muscle at rest
On top of adding extra TDEE of course these as mentioned , their primary purpose being to hold onto muscle on large deficits , it is still important to provide muscle stimulus and hit protein.
Now moving onto the real heavy hitting fat burning agents
T3 + T4
Mechanism
Energy is dissipated as heat via mitochondrial proton leak rather than stored as ATP.
T4 contributes primarily via peripheral conversion to T3 by deiodinases D1/D2, particularly in liver and skeletal muscle. At 50mcg exogenous T3, endogenous TSH and T4 production are fully suppressed.
REE corrected for lean body mass fell from 42 ± 6.7 kcal/24h/kg LBM in the hyperthyroid state to 33 ± 4.4 kcal/24h/kg LBM after treatment (−21%, P < 0.0001). fT3 (P < 0.0001) and fT4 (P = 0.0001) were independent predictors of REE.
At 75kg LBM, the 21%/kg LBM figure translates to 550 kcal/day from the T3 state alone
Essentially the more lean mass you have now the more mogger T3 will be
T4 supplementation raised RMR by a mean of 60 ± 109 kcal/day (4.0 ± 6.8%, P = 0.06) with high individual variability (range: −119 to +252 kcal/day). Resting RQ increased significantly; exercise efficiency unchanged.
Though our main reason to run T4 is not for the fat loss itself but rather its effects for our brain , it relies heavily on D2 mediated local T4 to T3 conversion rather than taking up circulating T3 directly. Theoretically, running T3 only could leave CNS T3 signalling somewhat blunted relative to the periphery
T3 will also work to make other adrenergic agonists in this stack work better
BMR was significantly higher in the subclinical hyperthyroid state vs hypothyroid state (3.8 vs 4.4 kJ/min, P = 0.012). Non-shivering thermogenesis rose from 15 ± 10% to 25 ± 6% of total thermogenesis (P = 0.009). BAT standard uptake value increased from 2.4 ± 1.8 to 4.0 ± 2.9 (P = 0.039).
T3 pre activates BAT, amplifying the response to adrenergic agonists like clen and mirabegron
T3 is not muscle sparing meaning higher doses will be anti catabolic , our anabolic bases will offset this massively already but I still recommend not pushing above 50mcg daily
Clenbuterol 80mcg
Mechanism
Clenbuterol is a selective β2-adrenergic receptor agonist with partial β3-AR activity.β2-AR activation raises intracellular cAMP via adenylyl cyclase, activating PKA which phosphorylates hormone-sensitive lipase (lipolysis), SERCA pumps (futile Ca2+ cycling), and UCP3 (mitochondrial uncoupling). The β3-AR component contributes to BAT thermogenesis
Clenbuterol increased resting energy expenditure by 21% (P < 0.001) and fat oxidation by 39% (P = 0.006). Phosphorylation of mTORˢᵉʳ²⁴⁴⁸ rose 121% (P = 0.004) and PKA substrates 35% (P = 0.006). Circulating fatty acids rose 180% (P = 0.001)
A 21% acute REE increase on a natural RMR of about 1,700–1,800 kcal/day = ~360–380 kcal/day.
It is important to note with clen β2-AR downregulation attenuates the response so it is best to cycle 2 weeks on 2 weeks off to keep the receptors sensitive
You can also combine with nebivolol which a very selective B1 blocker to counteract some of the effects clen can have on heart rate.
Mirabegron 200mg
Mechanism
Mirabegron is a selective β3-adrenergic receptor agonist.Human β3-ARs are expressed in brown adipose tissue, bladder, skeletal muscle, and heart. β3-AR activation in BAT increases UCP1-mediated proton leak via cAMP/PKA. The β3-AR has been identified as responsible for >40% of ephedrine-induced thermogenesis in human skeletal muscle
200 mg oral Mirabegron increased resting metabolic rate (RMR) by 203 ± 40 kcal/day
and this is without being primed in a T3 environment (increased BAT)
250–350 kcal/day in a T3 primed BAT environment is a fair assumption to make
Empagliflozin
Empagliflozin is an SGLT2 inhibitor , it blocks glucose reabsorption in the proximal tubule of the kidney, forcing urinary glucose excretion. The caloric loss mechanism is straightforward in that the glucose that would have been reabsorbed and metabolised is instead excreted in urine.
The clinical data on urinary glucose excretion at 10mg
- Empagliflozin 10mg causes approximately 70–80g of glucosuria per day in diabetic patients
- In non diabetic individuals the figure is lower at about roughly 50–70g/day because blood glucose is already tighter and there's less filtered load to block
- 1g glucose = 4 kcal
- 60g glucosuria × 4 kcal = 240 kcal/day
Main hunger suppression agents
Obviously when you are driving your TDEE up , you will subsequently be hungry as fuck , so we need to nuke our appetite to death
Retatrutide 6mg+
Mechanism
Retatrutide is a GLP-1/GIP/glucagon triple receptor agonist. The glucagon receptor (GCGR) arm is the primary thermogenic vector.GCGR activation on hepatocytes, adipocytes, and BAT raises intracellular cAMP and PKA activity, driving fatty acid oxidation and non shivering thermogenesis
And of course GLP-1 receptor nuking your appetite.
In human studies with exogenous glucagon infusion (not retatrutide specifically):
- Low dose glucagon increases EE in healthy humans — one frequently cited study showing ~0.08 kcal/min increase, which extrapolates to roughly 115 kcal/day
- But this is pharmacological glucagon bolus, not a long-acting GCGR agonist at therapeutic doses, so the comparison is imperfect
Cagrilinitide 2.4mg+
Mechanism
Cagrilinitide is a long acting amylin analogue that is not yet FDA approved
It is an investigational once weekly injectable peptide designed to mimic the natural hormone amylin which is co secreted with insulin from pancreatic beta cells.
Amylin plays a key role in regulating appetite and glucose metabolism by promoting satiety, slowing gastric emptying, and reducing food intake.
This hits a completely different pathway than GLP1 agonists for appetite suppression and is why it is often used in conjunction with them , as well as them being mechanistically very synergistic.
Bonus
Androgen × β-AR Synergy
Supraphysiologic androgens expand the β-adrenergic receptor pool in skeletal muscle and adipose tissue. Clenbuterol and mirabegron therefore operate on a receptor population that is actively upregulated by the androgen load, multiplicatively increasing the thermogenic output of both compounds relative to what a eugonadal individual would experience.AR activation suppresses β-adrenoceptor-mediated CREB activation and UCP1 expression in primary brown adipocytes from male mice, suggesting that high androgen levels may partially attenuate BAT-specific thermogenesis. (PMC9700029)
This creates a partial offset in BAT, but skeletal muscle thermogenesis (via UCP3, adrenergic response, and T3 interaction) dominates the androgenic thermogenic contribution.
Net effect is strongly positive.
T3 × β-Adrenergics
T3 transcriptionally upregulates β-AR density in skeletal muscle and adipose. Supraphysiologic T3 therefore expands the receptor pool that both clenbuterol (β2-AR) and mirabegron (β3-AR) act on, generating greater cAMP per unit drug. T3 also directly upregulates UCP1, UCP2, and UCP3 expression , stacking on top of tren’s UCP3 upregulation and clen’s PKA-mediated UCP phosphorylation. Three distinct regulatory inputs converging on the same mitochondrial uncoupling endpoint.
Retatrutide GCGR × T3 (Hepatic Substrate Oxidation)
Glucagon driven hepatic cAMP/PKA signalling and T3-driven upregulation of hepatic fatty acid oxidation enzymes converge on the same metabolic outcome via distinct transcriptional mechanisms. Additive to potentially synergistic at the hepatic oxidation level
T3 × Tren UCP3 (Mitochondrial Uncoupling Amplification)
Both T3 and trenbolone independently upregulate UCP3 in skeletal muscle through different receptor systems (TRβ and AR respectively).
Combined, the transcriptional drive on UCP3 expression is greater than either alone, producing enhanced proton leak and heat production per unit of skeletal muscle mass.
If retatrutide and cagri alone are not enough to curb your appetite there are a few extra things we can implement
Semaglutide (low dose)
The obvious one. Reta already hits GLP-1R but semaglutide at 0.5–1mg weekly would add additional GLP-1R occupancy via a different pharmacokinetic profile
Or instead we can swap out reta for tirz as tirz also has a high affinity for GLP-1 but will also provide the insulin sensitivity benefits.
MC4R agonism
Melanocortin-4 receptor agonists directly activate the hypothalamic satiety pathway downstream of leptin. Relevant here because one of the main reasons hunger breaks through on extended cuts is leptin decline.
Tesofensine
Tesofensine is a triple monoamine reuptake inhibitor , it blocks reuptake of dopamine, noradrenaline, and serotonin simultaneously , the triple reuptake mechanism is hitting the entire monoaminergic reward/appetite system at once
Now factoring everything if we take into account this is the estimate we would have for a 75kg 20% body fat male
Lean Body Mass = 60kg
- Estimated natural RMR (Cunningham formula): ~1,750 kcal/day
- Estimated natural TDEE (moderately active + training): ~2,500 kcal/day
T3 50mcg = 540 kcals/day
Clenbuterol 80mcg = 365 kcal/day
Mirabegron 200mg = 250 kcal/day
Test 300mg + Tren 70mg effect = 275 kcals/day
Retatrutide 6mg+ = 150 kcals/day
Synergistic mechanism additions = 150 kcals/day
Empagliflozin 10mg = 240 kcals/day
Total estimated increased TDEE = 1970 kcals/day
